A cryptic meprin-like proteolytic activity in mouse kidney brush border membranes.
1. Inbred mouse strains differ markedly in the expression of a kidney brush border metalloendopeptidase, meprin-a. 2. Brush border preparations from mice of the low-meprin-a phenotype (specific activities less than 5% of the high-meprin-a trait) contain a metallo-endopeptidase, meprin-b, that is larger than meprin-a, and which is inactive unless the membrane preparations are treated with trypsin. 3. This cryptic metallo-endopeptidase has been previously postulated to be a stalled precursor of meprin-a. 4. We show here that meprin-b is present in all mice-high and low meprin-a phenotypes--and that this activity is similar in substrate specificity and amount present in the brush border. 5. Meprin-b may therefore be a distinct gene product that is independent of meprin-a phenotype.
Macadam
G C
GC
Department of Biochemistry, University of Liverpool, England.
Beynon
R J
RJ
Bond
J S
JS
D000818:Animals; D015153:Blotting, Western; D003374:Coumarins / Q000378:metabolism; D004151:Dipeptides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D006868:Hydrolysis; D007668:Kidney / Q000201:enzymology* / Q000648:ultrastructure; D008666:Metalloendopeptidases / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008871:Microvilli / Q000201:enzymology; D010206:Papain / Q000494:pharmacology; D010641:Phenotype; D011498:Protein Precursors / Q000378:metabolism*; D013379:Substrate Specificity; D008625:Tiopronin / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology
D003374:Coumarins; D004151:Dipeptides; D011498:Protein Precursors; C021159:benzyloxycarbonyl-phenylalanylarginine-4-methylcoumaryl-7-amide; D008625:Tiopronin; D014357:Trypsin; D010206:Papain; D008666:Metalloendopeptidases